This invention relates to a concrete wall unit, and more particularly to a cap unit for a retaining wall.
In a retaining wall constructed of a plurality of courses of concrete blocks, it is known to form the uppermost course in the retaining wall of a series of cap units to cover the hollow cores of the blocks forming the lower retaining wall courses.
A particularly advantageous block structure for constructing a retaining wall is disclosed in my co-pending application Ser. No. 07/304,793 filed Jan. 31, 1989. The retaining wall block therein disclosed includes a rear web having a recess formed in its upper surface, with a clip adapted for placement therewithin. The clip has depending inner and outer legs for engaging the inner and outer surfaces of the rear web, and an upper portion therebetween which is adapted for placement within the recess. An upstanding portion of the clip projects upwardly above the upper surface of the block to which the clip is mounted, for engaging the inner surface of the rear web of a block in the course thereabove.
The present invention provides a cap unit block structure for use on a retaining wall constructed of a plurality of courses of blocks as described. A plurality of cap units according to the invention are adapted for side-by-side placement atop the uppermost course of retaining wall units to form the topmost block course and to cap off the retaining wall so constructed. In accordance with the invention, a retaining wall cap unit comprises a cast concrete block having an upper surface, a lower surface, first and second end surfaces and first and second side surfaces. The upper surface of the cap unit is substantially solid so as to provide a cavity-free cap to the retaining wall. A cavity is formed in the bottom surface of the unit, and is adapted to receive the upstanding portion of the clip mounted to a block in the course therebelow. In a preferred embodiment, the cavity preferably comprises a slot extending throughout substantially the entire width of the cap unit bottom surface between the first and second side surfaces. The cap unit is constructed so that one of the first and second end surfaces is narrower in width than the other of such surfaces. To provide this structure, one of the side surfaces is disposed so as to be substantially perpendicular to both the first and the second end surfaces, while the other of the side surfaces is disposed in a non-parallel relationship to the first-mentioned side surface. With this construction, a straight run is provided by alternately placing the cap units so that one cap unit has its narrow end surface facing outwardly while the adjacent cap unit has its wide end surface facing outwardly. To form an inside radius of curvature, the cap units are placed so that adjacent cap units all have their narrow end surface facing outwardly. Conversely, to form an outside radius of curvature, the cap units are placed so that adjacent cap units all have their wide end surfaces facing outwardly. To accommodate the alternating placement of the cap units to provide a straight run as well as inside and outside curvatures, a pair of cavities as discussed previously are provided on the bottom surface of the cap unit. The cavities are disposed on the bottom surface of the cap unit such that one cavity is located adjacent one of the end surfaces and the other cavity located adjacent the other of the end surfaces. In this manner, no matter which way the cap unit is oriented on the block in the course therebelow, a cavity is provided for receiving the upstanding portion of the clip which is mounted to the lower block.